A conventional memory module comprises a module board and a plurality of volatile memory components surface-mounted on the module board for plugging the module into a memory socket of a computer system. As the working frequency of memory components becomes higher, memory modules have higher data transmission rates with larger power consumption. Therein, heat will accumulate in memory modules leading to system instability. When working temperatures of memory modules become higher and exceed the tolerance, the performance of memory modules significantly drops. At the same time, the Soft Error Rate (SER) of memory modules also significantly increases. Accordingly, the working temperatures of memory modules are expected to be accurately monitored and implemented.
It is an existing technology that LED components are disposed on a memory module. However, the known light emitting mechanism only roughly shows the difference between high temperature and normal temperature. It is difficult to achieve accurate programmable modulation of diversified temperature-sensing scenario modes. As disclosed in Taiwan utility Patent No. TW-M448772 entitled “Dynamic Random Access Memory”, a conventional memory module comprises a module board, a plurality of LED components and a translucent light bar. The LED components are physically disposed on and electrically connected to the module board. The light bar is disposed on the module board with a direct connecting relationship to cover the LED components in a matter that light emitted from the LED components penetrates through the light bar. Therein, the disposition of the light bar is that a side of the memory module is directly clamped in a slot of the light bar. There is at least a recess formed on the sidewall of the slot of the light bar to accommodate LED components inside the slot of the light bar. Furthermore, a light-emitting controller for controlling the LED components is also disposed on the module board. Therein the light-emitting controller includes a temperature sensor to measure operating temperatures, to convert the measured temperature into a signal and to feedback to the light-emitting controller to modulate the emitting frequency of LED components according to the measured temperature. Through different light-emitting-frequency of the LED components, end users are reminded if the operation temperature of memory modules is over-heated or not. The light-emitted control system of a conventional light-emitting memory module is an independent system with an independent temperature sensing system, an independent signal system and an independent power system. Thus, the manufacture cost of memory modules is greatly increased. Moreover, the new temperature sensing system to control light emitting frequency and the built-in temperature sensing system of memory modules to control refreshing frequency are two different systems. Therein, the sensing locations and the structures of the temperature sensors are different leading to different sensing temperatures. Furthermore, the light-emitting mode only roughly shows if memory modules are overheated or not without accurately correlate the working temperature of memory modules to the sensing temperature of the light-emitting system. Therein, it is very difficult to implement accurately adjusting temperature-sensing scenario modes according to operating temperatures.